Abstract:
The structure-directing effect of two amphiphilic dopants on the nucleation
and growth mechanism during the formation of micro/ nanostructured polyaniline
(PANI) and polyaniline-clay nanocomposites (PANICNs) is described. PANIs and
PANICNs were prepared by in-situ intercalative emulsion polymerization of aniline
using the amphiphilic dopants, 3-pentadecyl phenyl phosphoric acid (3-PDPPA) and
3-pentadecyl phenol–4-sulphonic acid (3-PDPSA), derived from cashew nut shell
liquid, a renewable resource. These molecules act as intercalating agents, dopants
and also as structure-directing agents. X- ray diffraction (XRD) and scanning electron
microscopic (SEM) studies revealed the formation of lamellar/fibrillar – network in
PANI- PDPPA and cylinder/rod morphology in PANI-PDPSA. Experimental data reveal
that fibrillar morphology arises from the heterogeneous nucleation followed by an
indefinite growth mechanism. On the other hand rod-like structures are formed from
the self-assembled rod-like micelle guided polymerization through homonucleation
followed by an anisotropic growth mechanism. Electrical conductivity measurement
revealed lower conductivities for PANICNs than that of PANIs.